There are two ways to make technology terrifying. You can place it in the wrong hands — the rogue government agency, the power-hungry corporation, the monologuing supervillain. Or you can suggest that there are no right hands, that our machines are corrupting society from the bottom up.

The first approach gets you a gadget-driven action movie, a ’70s-style paranoid thriller, a Bourne or Bond film. The second approach gets you a dystopia, with the BBC anthology series Black Mirror being the most powerful recent example. In Mirror, the various brave new worlds of social-media tyranny have no villain, no mastermind, not even a Mustapha Mond to explain it all — just the crushing horror of realizing that we built this nightmare for ourselves, brick by brick and click by click.